Known barcode sensor systems generally use lasers in conjunction with conventional lenses or other optics for focusing or concentrating sufficient laser radiation on the bar code to be scanned. The systems additionally include detectors also in conjunction with conventional optics for receiving light reflected from a target area of the bar code and providing an output signal representing the bar code. Other barcode sensor systems utilize light emitting diodes (LEDs) as the light sources instead of lasers.
A known bar code sensor of the prior art, for example the bar code sensor 300 shown in FIGS. 9A & 9B of the accompanying drawings, includes a light source and photodiode dies molded into components (not shown), a PCB 301 onto which the light source and photodiode components (not shown) are populated, processing circuitry 302 for processing the sensor signal also populated on the PCB, a housing holding lenses and into which is inserted and glued the PCB with light source and photodiode components thereon, and a housing cover 304 assembled to the housing to enclose the components and lenses within the housing.
The aforementioned known barcode systems are generally of large dimensions owing to the large space requirements of bulky lenses or other optics necessary for concentrating sufficient illumination both on the bar code to be scanned and the detector after reflection from the bar code target area. The optics of such systems are complicated to align and assemble and suffer from optical inefficiencies which result in short working distances and higher than necessary power consumption requirements to compensate for these optical inefficiencies. High manufacturing costs and inefficient and unreliable operation of these bar code sensor systems limit their applications in many fields.
The aforementioned problems demonstrate that there is a need to provide a low cost, compact bar code sensor which is capable of operating in an efficient manner.